The present disclosure relates to an image forming apparatus that includes a facsimile portion connected to a telephone line and a communication system that includes such an image forming apparatus.
Conventionally, various types of systems are proposed that are connected to a network and that control, according to a specific protocol from the network, transfer to a power-saving mode and the return to a normal mode in a device. Here, the normal mode refers to a mode in which power is supplied to the individual portions of the device and thus it is possible to achieve a predetermined function (for example, in an image forming apparatus, a copying function), and the power-saving mode refers to a mode in which the supply of power to part of the device is stopped and thus power consumption is reduced as compared with the normal mode.
For example, a network device is known that includes: a setting means which sets return conditions corresponding to a protocol followed by a data packet received through a network and used for returning a device from a power-saving mode; and a return means which returns, when a data packet following a specific protocol is received, the network device from the power-saving mode under the return conditions set by the setting means. The network device is intended to provide, even when a user is not a skilled person, a more significant power-saving effect with consideration given to a protocol followed by data received through the network so as to cope with a problem in which unnecessary packet reception increases the number of times the network device is returned from the power-saving mode to inhibit the function of the power-saving mode and a problem in which in a conventional network power-saving control technology, operations such as the selection of a protocol type are complicated and excessively technical such that it is difficult for the user to understand them.
Incidentally, in recent years, the form has been increased in which a multi-function peripheral called a so-called MFP (Multi-Functional Peripheral) having functions such as a copying, a facsimile, a scanner and a printer is connected to a network such as an Ethernet (registered trademark) or a wireless LAN (Wireless Local Area Network) and is utilized. In such a multi-function peripheral, a network control portion called a NIC (Network Interface Controller) is connected to the network and is operated, and thus it is possible to monitor whether or not data transmission from the network to the own multi-function peripheral is performed. Hence, in the power-saving mode, power is supplied to at least the network control portion, and when data transmission from the network to the own multi-function peripheral is performed, it is possible to return the multi-function peripheral to the normal mode.
In a multi-function peripheral having a facsimile function (facsimile portion), the following configuration is generally adopted: as described above, data transmitted from the network is received in the network control portion, and thus the multi-function peripheral is returned to the normal mode, and in addition, even when a call signal (ringer signal) is received in the facsimile portion through a telephone line which is a separate communication line from the network, the multi-function peripheral is returned to the normal mode. In other words, in general, in the power-saving mode, the multi-function peripheral described above stops the supply of power to the main circuit (for example, a CPU; Central Processing Unit) of the facsimile portion, and can detect only the reception of the call signal with the minimum required power.
On the other hand, nowadays, environmental regulations for power saving are tightened, and when the facsimile portion (for example, a circuit board where circuits on facsimile communication are collected) is not connected to a telephone line, it is required to detect the fact thereof and rapidly transfer the power-saving mode to a mode (for convenience, this mode is referred to as an “off mode”) in which the supply of power to the entire facsimile portion is stopped and thus power consumption is lowered. As a situation in which the facsimile portion is not connected to a telephone line, for example, a case (modular line disconnection) where a modular line connected to the telephone line is intentionally disconnected by a user from the main body of the multi-function peripheral can be assumed. Whether or not the facsimile portion is connected to the telephone line can be determined through the detection of a line voltage applied to the telephone line by the facsimile portion. For example, when 0V is detected as the line voltage, it is possible to determine that the connection to the telephone line is disconnected.
However, even when a power failure temporarily occurs in a switching station connected to the telephone line or even when the multi-function peripheral is connected to the telephone line through a private branch exchange within a building, and a power failure temporarily occurs in the private branch exchange (hereinafter also referred to as a “power failure in a switching station or the like”), the line voltage detected by the facsimile portion of the multi-function peripheral is 0V, and this state is the same as that of the modular line disconnection. Hence, when a power failure in a switching station or the like is determined to be a modular line disconnection, and thus in order to satisfy the requirement of the environmental regulation described above, the multi-function peripheral is easily transferred to the off mode, at the time of recovery from the power failure in the switching station or the like, it is impossible to detect an incoming call (the reception of a call signal) from the telephone line (because in the off mode, the supply of power to the entire facsimile portion is stopped), with the result that it is impossible to detect an incoming call to return to the normal mode. Under these conditions, after the recovery from the power failure, it is impossible to transmit and receive data in the facsimile portion.
Hence, preferably, when the connection to the telephone line is disconnected, the cause of the line disconnection, that is, whether or not the line disconnection occurs without the intention of the user as in a power failure in a switching station or the like is appropriately determined, and the transfer to the off mode is controlled.
Conventionally, no technology is available in which in a configuration including a facsimile portion, when the connection to a telephone line is disconnected, the cause of the line disconnection is appropriately determined, and thus the transfer to the off mode is controlled.